Hello.,

  95 tahoe 350, recent fuel filter change.  Have changed plugs, wires, cap and rotor, o2 sensor, ignition module, alternator. It's been missing and hesitating for a while now.  It has slowly over time required more and more time to start.  Now it takes 2 minutes or so to start if at all.  I smell gas as I am cranking it.  If it does start, it runs VERY poorly.  Sometimes stalling at idle.  If I have the defrost on high or the lights on, it adds to the problem.  Very very bad acceleration. The plugs have about 3000 miles on them.  Could they foul already?  It's not a pretty truck, but she's still my baby.  Any help would be greatful.

do you have a check engine light on?